I had bought the Mobile Internet on Hotlink, 350MB/month for few times now. I only use Whatsapp and nothing else. Just lately, the 350MB data was used up even when I am not using whatsapp or internet. The data just got used up like that without any application or internet running.

I called up the Hotlink Customer Service to lodge a complaint and they suggested that I watched video and Youtube and the data will be used up very quickly. I told them off and said I did not visit these sites. I suggested someone is stealing the data and asked them to put in case for me. So they put in a case for me and asked me to wait 3-5 days for a response. After waiting for a day, I again figured out 10MB of data was gone again without me using the phone. I then called Hotlink to expedite.

On the same evening, I received a call from Hotlink and the lady on the line told me they cannot check on it and couldn't do anything about. She suggested (again) that I may have watched video on Youtube that used up all the data. She couldn't wait to put down the phone as I expressed my disappointment on this matter.

Has anybody encountered this problem? Your data being used up when you don't use the internet at all? I may consider paying a visit to Hotlink to see the manager there.

What other data plans are there on the market that users can have access on the information(data) that have been used? Some sort of tracking. I'm planning to boycott Hotlink for this shit service I have encountered lately.

I am using Symbian. Data usage is irrelevant as no application is running.

The data is not stolen, it is your phone background sending data, those free apps or default apps are responsible for that.

Even that your phone are clean / factory default, your phone already include those free apps that background collect data tru your phone.

Hence, turn off data on your phone or don't use smart phone!

Highly possible background apps is consuming the data which you wont know and you cant detect. As mentioned above, pls install a data monitoring apps to get some evidence.

My phone doesn't have any apps that you claim are responsible for using up the data. The data was intact with all the same apps previously, and just lately the data was used up.

Since the above is speculation unless proven otherwise, you may choose to reword your sentence to "The data MAY NOT be stolen, it is your phone background that MAY be sending the data...". Since you are not the phone user and you do not have any idea what apps are on my phone, all suppositions are based on your instincts and pure guessing.

For your information, some Symbian Nokia do have internet access. It's just like old Sony Ericsson also able access internet, also having background data transfer.

For you information, if you receive MMS, that data in KB also will count on you.

Pro Advice: please told Maxis CS that you are using Nokia 3310, and how come have internet charges 
That's will solve your problem

I faced the same problem like TS. But I'm using Digi Internet Prepaid Broadband. This happened a few months ago. TS only lost 350 MB of data, me lost like 3-4 GB of accumulated data after topping up for quite long time. Considering I'm able to accumulate the data capacity months after months, how did the data limit just disappeared overnight? I would like to know too. Called Digi helpline and they mentioned the same thing like what happened to TS. Background data running, downloading Youtube and etc, are not my cup of tea and even after checking my apps data usage, I still cannot tally the total data that went missing. I wish TS good luck in searching for the truth,I stopped at calling the Help Line and don't bother to ask anymore. Nowadays, I rarely use the sim cards anymore. Occasionally topping up just to keep it active.